This nonprovisional application claims priority under 35 U.S.C. xc2xa7119(a) on Patent Application No. 091215568 filed in TAIWAN, R.O.C. on Oct. 2, 2002, which is herein incorporated by reference.
1. Field of the Invention
The invention relates to a color wheel and a washer thereof, and in particular, to a color wheel and a washer of the color wheel, both of which are used in the projection technology.
2. Description of the Related Art
Digital Light Processing (DLP) is a widely used projection technology. DLP has several advantages, including, high brightness, accurate tone reproduction, a fast response time, noise-free operation, and thin and light composition.
In a DLP projector, a digital control method and a reflection principle are adopted. Light rays from the light source are collected and focused by the lens to pass through three color filters. The light rays are then projected onto a Digital Micro-mirror Device (DMD). Since the DMD includes several movable micro mirrors, driving electrodes may control the tilt angle and deflection time of each movable mirror. Then, the light rays are projected to form an image by switching the direction of the light ray reflections.
In the DLP projector, a color wheel 4 for generating the light rays of several colors is generally provided. Referring to FIG. 1, the color wheel 4 mainly includes a motor 41, a color filter 42 and a washer 43. The washer 43 and the color filter 42 are mounted on the motor 41. In this case, the motor 41 includes a housing 411 and a motor body 412, which rotates together with the housing 411.
Additionally, the color wheel is also used in Liquid Crystal on Silicon (LCOS) projectors and Liquid Crystal Display (LCD) projectors. Herein, the function of the color wheel is the same as in DLP projectors for separating the light rays into several colors.
In general, the motor for the color wheel rotates at a speed higher than 7200 rpm. When the rotation center of the motor is away from the central axis of the rotation shaft (i.e., when the rotation center is not located on the central axis of the rotation shaft), the operation of the color wheel may be adversely influenced by vibration and noise. Further, the operational reliability of the color wheel may decrease. In addition, the color filter and the washer are mounted on the housing by using an adhesive. When the color filter and the washer are coated with too much adhesive, or the relative position of the color filter and the washer is moved, the adhesive may overflow. In this case, the overflowing adhesive may pollute the color filter. Further, the definition and the clear scope of the color filter may be decreased.
It is therefore an important objective of the invention to provide a color wheel and a washer of the color wheel to solve the problem mentioned above.
An objective of the invention is to provide a color wheel and a washer of the color wheel, each of which may have the advantages of correcting the rotation center, reducing vibration and noise, avoiding adhesive overflow, proving the definition and the clear scope of the color filter, and improving the operational reliability of the color wheel.
To achieve the above-mentioned objective, the invention provides a color wheel including a motor, a color filter and a washer. The color filter is set on the motor. The washer is set both on the motor and the color filter and the color filter is set between the washer and the motor. In this case, a circumferential washer surface is formed with a groove and a recess is formed between a circumferential edge of the outer surface of the washer and the color filter. In addition, the invention also provides a washer of the color wheel.
As mentioned above, the invention provides a color wheel and a washer of the color wheel, in each of which a specific groove is formed in the washer. Compared to the prior art, the difficulty of positioning in this invention may be decreased by fitting or adhering the counterpoise into the groove of the color wheel. Furthermore, since the counterpoise may be placed totally within the groove, it is free from collisions. Also, the influence on the counterpoise caused by centrifugal force is reduced. Moreover, since the rotation center of the color wheel may be corrected, the vibration and noise caused by the color wheel is further reduced. In addition, the recess between the washer and the color filter may absorb an excess of adhesive between the color filter and the washer. In other words, an excess of adhesive may flow into the recess, so that the pollution of the color filter caused by the adhesive is avoided. Furthermore, the definition and the clear scope of the color filter are proved, and the operational reliability of the color wheel is also improved.